In PHP programming, there are two ways to express time, one is timestamp, and the other is string format. The timestamp refers to the number of seconds that have elapsed since 1970-01-01 00:00:00, which is a fixed integer value. String format can represent various time formats, such as "2019-08-08 08:08:08" etc.
In PHP programming, we sometimes need to convert time in string format into a timestamp. Here are some simple methods for reference.
Method 1: PHP built-in function strtotime()
PHP built-in function strtotime() can convert string time into timestamp. Using this function is very simple, just use the time string as a parameter of the function, as follows:
$date = "2019-08-08 08:08:08"; $timestamp = strtotime($date);
The above code converts the date string "2019-08-08 08:08:08" into time Stamp and assign the result to the variable $timestamp.
It should be noted that this function is only applicable to formatted date strings, such as "2019-08-08 08:08:08", and cannot be applied to string formats such as "Wednesday".
Method 2: DateTime class
The DateTime class in PHP can also convert a time string into a timestamp. First, you need to create a DateTime object, and then use the object's getTimestamp() method to obtain the timestamp, as follows:
$date = "2019-08-08 08:08:08"; $dateTime = new DateTime($date); $timestamp = $dateTime->getTimestamp();
The above code converts the date string "2019-08-08 08:08:08" into a DateTime object , and use the object's getTimestamp() method to obtain the timestamp.
It should be noted that if you use the DateTime class to process time zone information, you need to pass in the DateTimeZone object when creating the DateTime object.
Method 3: mktime() function
The mktime() function can create a timestamp based on the specified time information. To use this function, you need to specify the hour, minute, second, month, day, and year. and other information, as follows:
$timestamp = mktime(8, 8, 8, 8, 8, 2019);
The above code converts 8 hours, 8 minutes and 8 seconds on August 8, 2019 into a timestamp.
It should be noted that this function is only suitable for conversion when the specific time information is known. If there is only a date string, this function cannot be used for conversion.
Summary
The above are several simple methods to convert time strings into timestamps in PHP. In actual development, different methods should be selected according to specific needs.
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